I need a Flutter App expert

I used Fivvr to partially create an app that tracks rowing challenges over a map for teams of up to four. I am not seeing the sort of results I hoped for. Ideally, you would have experience with google maps and databases. They started the project in flutter and got about 70% of the way done, but I am not happy with their results or their diligence. We are 3 months over time on a 3 month project.